Attenuation of the seismic dispersion associated to foothills topography: application to real data
Abstract
Land seismic data is contaminated commonly with coherent and high amplitude back-scattered noise generated from roughness in the surface topography; these events make generally the key information on deeper layers unclear. In Colombian foothill areas with rough topography and high lateral velocity variation, this noise has been difficult to attenuate. Conventional methods aimed at this purpose usually yield unsatisfactory results. We present a strategy based in prediction and subtraction of the unwanted waves. Assuming knowledge of the source wavelet and the shallow velocity model we use a finite-element solution of the acoustic wave equation to model the back-scattered noise; this modeled response is then subtracted from the prestack data, resulting in a noticeable attenuation of noise in field seismograms. The method was applied to prestack real data from colombian foothills in order to observe the enhancement in seismic records, planning in a close future to show results on stacked data.
References
Bevc, D., 1996." Flooding the topography: wave equation datuming of land data with rugged acquisition topography". Geophysics, 61 (5): 1558-1569 . https://doi.org/10.1190/1.1444258
Ernst, F., Herman, G. C. and Ditzel, A., 2002."Removal of scattered guided waves from seismic data: geophysics". SEG, 67 (4): 1240-1248 . https://doi.org/10.1190/1.1500386
Fu, L. Y.,Guan, H. and Wu, R. S., 1999. "Removing rugged-topography scattering effects in surface seismic data". 69th Ann. Internat. Mtg: SEG, 453-456. https://doi.org/10.1190/1.1821050
Guan, H., Wu, R. S. and Fu, L. Y., 2000. "Removing scattering effects of rugged topography using finite-difference method". 70th Ann. Internat. Mtg: SEG, 2189-2192. https://doi.org/10.1190/1.1815885
Kou-Yuan, H. and Shen-Pyng, W., 2000. "Neural networks for seismic wavelet extraction and clustering". 70th Ann. Internat. Mtg: SEG, 741-744 .
Langtangen, H. P., 1999. "Computational partial differential equations: numerical methods and diffpack programming". Springer Verlag.
Langtangen, H. P., 1996. "Efficient element solution of the linear wave equation in diffpack". The Diffpack version 1.4 Report Series, SINTEF, University of Oslo .
Sarma, G. S., Mallick, K. and GadhinGlajkar, V. R., 1998. "Nonreflecting boundary condition in finite-element formulation for an elastic wave equation". Geophysics, 63 (3): 1006-1016 . https://doi.org/10.1190/1.1444378
Segerlind, L. J., 1984. "Applied finite element analysis". John Wiley & sons.
Yang, K., Wang, H. and Ma, Z., 1999. "Wave equation datuming from irregular surface using finite difference scheme", SEG Technical Program with Biographies, 69th Annual Meeting, Houston, Texas, 1465-1568. https://doi.org/10.1190/1.1820795
Yilmaz, O., 1991. "Seismic data processing". SEG, Investigations in Geophysics, (2) .
Zienkiewicz, O., 1992. "El método de los elementos finitos". Vol. 2, McGraw Hill.
Downloads
Copyright (c) 2003 Creative Commons Reconocimiento-NoComercial-CompartirIgual 4.0.
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.